Transmission lock



Patented May 1, 1928.

warren STATES PATENT OFFICE;

PERRY L. TENNEY, F MUNCIE, INDIANA, ASSIGNOR T0 GENERAL MOTORS COR-PORATION, 0F DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

TRANSMISSION LOCK.

Application filed August 15, 1924!. Serial No. 732,239.

This invention relates to vehicle locks, and is illustrated as embodiedin a key-controlled lock for an automobile transmission.

One object oftheinvention isto provide l a simple lock having anangularly-movable bolt for a transmission oi' the type having shifterforks with sliding plate-like supporting portions, one or the other ofwhich is locked inidle position byk an interlocking plate shiftedtransversely `by the gear-shift lever. In one desirable arrangement thebolt locks one shifter fork directly, as by having a portion arranged tobe turned into ra notch in the edge of the fork, and locks l5 the otherfork indirectly through the interlocking plate. y 'I`heinterlockingplate is shown with a notch in its edge which ex `tends inwardly andthen parallel to theV edge, to define a finger behind which a sec ondlocking portion of the bolt 1s turned to lock the plate againsttransverse movement while it isinterlocked with the other shifter fork.

Another object of t-he invention is to force 2:5l the driver to use histransmission lock, byV

having an electric switch, preferably the ignitionswitch, mounted on thetransmission and operated by the transmission lock, so that thetransmission must bev locked to shut off theengine. A simple andreliable arrangement of this character is provided, the novelieaturesbeing pointed out in the appended claims.

The above and other objects` and features following description of oneillustrative embodiment shown in the accompanying drawings, in which:

Figure 1 is a horizontal section through the top of a transmission,showing the means for opening and closing the switch from the lock;

Figure 2 is a vertical section on the line -2f2 of Figure 1; t

Figure 3 is a side elevation of the bottom of the key-controlled lockingbolt; Y

Figure i is a top plan view of part of the interlocking plate, showingthe notch for the locking bolt; Y f

Figure 5 is a top plan view yof part of one of the invention will beapparent from the v or the shifter forks, showing the notch for thelocking bolt; i y

Figure (3 is a section corresponding to part of vFigure 1, but showingadifferent means for operating the switch plunger;

Figure T is a View showing the locking mechanism in plan.

The illustrated transmission is inclosed in a housing 10 withkadetachable cap 12 held by screws or bolts 14 which also serve to hold aVstamping or supporting plate 16 clanipedat its edges between thehousing and cap. The transmission is of the type in which the slidinggears are selectively shifted by one of two shifter forks 18 and 20,slidably supported between stamping 16 and an upper stamping securedthereto by bent integral lingers'e. Each shifter fork has a notch '76 inits outer edge, into one or the other of which projects thecorrespondingone of two downwardly-bent iingers 80, 82 cuan interlockingplate 26 having a longitudinal slot 28 embracing a plunger 30 yieldinglyurged bya spring 32 downwardly from af gear shift lever 84, and thelower end or' which enters one o a pluthereby yieldably hold the leverin the vas rious positions in which it may be placed. Thus theinterlocking plate is moved vtransversely by the gear shift lever tolock the idle shifter fork and to move the lower end of the plunger 30into one or the other oi' the notches 84, 84H, one in each shifter fork;the slot 28 permitting movement of the lever to operate the shifter forkwhich is not locked. A transmission of this type is described .in detailin my application No.. 637,-k

rality of depressions Soin the plate 16 to partly dened by a finger 50,so that the notch extends into the plate and then to the right (Figure4) parallel to the edge, to deline a shoulder 52 on finger 50, soarranged that when bolt La is turned to locking posi tion a half-roundsection 54 will be turned to hook behind the shoulder to preventtransverse movement of the interlocking plate, thus locking shifter fork2O indirectly through the interlocking plate.

Bolt t carries a projecting pin 56, op-

erable when the transmission is locked to' o. U v\. ly closing theignition circuit. ringers or brushes 6a are carried by an insulatingpanel 72 forming one end of a housing 74 threaded into an opening in thetransmission housing. ltwill be seen that the switch, including panel72, housing 7a, brushes 6a, plunger 5S, and spring 60, forms aself-contained unit which requires for assembly merely to be threadedinto the opening in' the transmission housing', when the transmission isunlocked, there being no joints or connections of any kind to be made.

ln Figure 6 is shown an arrangement for moving the switch plunger 58positively in both directions. Spring GO is omitted in this arrangement,and bolt 44 carried a two arm member 15G of resilient sheet metal, thelower arm of which is forked to engage under the head ofthe plunger tomove it in one direction and the upper arm of which engages the top ofthe head to move it in the other direction. This obviates reliance on aspring for moving the plunger in one direction.

While one illustrative embodiment of the invention has been described indetail, it is not the intention to limit its scope to that particularembodiment, or otherwise than by the terms of the appended claims.

I claim:

Y l. A combined transmission lock and electric switch mechanismcomprising, in coinbinatioii, a pair of gear-shifting members, aninterlocking plate cooperating with said members to prevent theirmovement, a keycontrolled locking bolt movable to lock one gear-shiftingmember directly and the other through the interlocking plate, anelectric switch, and means operated by movement of the bolt to open theswitch when the gearrecesso shifting members are locked and to close theswitch when they are unlocked.

2. fr transmission having, in combination, a supporting plate, tworeciprocating gear shifting members supported by said plate, and havingeach a notch so arranged that said notches may register with oneanother; an oscillating gear shifting lever having a spring pressedplunger at its lower end adapted to enter one or the other of saidnotches as said lever is moved sidewise pre paratory to shifting one ofthe gear shifting members aforesaid; and depressions rovided in saidsupporting plate and into which the lower end of said plunger enters, tothereby yieldably hold the vsame within the notch in the gear shiftingmember into which it is moved.

3. A transmission having, in combination,

unit merely by threading it into and out ofV the opening and beingoperative when in' place without other connection.

4;. A' transmission having, in combination, two shifter forks includingplate-like supporting sliding portions, an interlocking plate restingupon and shiftable transversely of the shifter forks to lock one or theother of them in idle position, the shifter forks being held againsttransverse movement and he interlocking plate being held `againstlongitudinal movement, a gear-shift lever engaging the interlockingplate and adapted to move it'transversely yand Which'lever adapted toengage the unlockedrshifter fork and to move it longitudinally, and akey-controlled locking bolt constructed and arranged 'for angular'movement to lock one of the shifter forks directly against longitudinalmovement and simultaneously to lock the' interlocking plate a ainsttransverse movement while the inter ocking plate isl in a positionlocking the other shifter fork against longitudinal movement.

A transmission having, in combination, two shifter forks includingplate-like supporting sliding portions, an interlocking plate restingupon and shiftable transversely of the shifter forks to lock one or theother of them in idle position, the shifterforks being held againsttransverse movement and the interlocking plate being held againstlongitudinal movement, one shifter fork having a notch in its side edgeand the interlocking plate havingin its adjacent side edge a notch cutinwardly andy then in a direet-ion parallel to said edge to form ahookshaped finger, a gear-shift lever for moving the interlocking platetransversely and for shifting the unlocked shifter fork longitudinally,and a key-controlled locking bolt arranged for angular movement andhaving a locking part turned into the shifter fork notchby such movementto lock the corresponding fork directly against longitudinal movementandhaving another locking partV turned by such angular movement behindthe finger to lock the interlocking plate against transverse movementand thereby ini PERRY L. TENNEY.

